1 INTRODUCTION H IJSER€¦ · Anees Mohammed H, Tisny D B Abstract—Global consumption of natural river sandis very high due to the extensive use of concrete. The non availability

International Journal of Scientific & Engineering Research, Volume 7, Issue 10, October-2016 23 ISSN 2229-5518

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Flexural and Shear Behaviour of RC Beams Using SCC by Partial Replace-

ment of Fine Aggregate with Granite Fines Anees Mohammed H, Tisny D B

Abstract—Global consumption of natural river sand is very high due to the extensive use of concrete. The non-availability of sufficient quantity of ordinary river sand for making concrete structures is affecting the growth of construction industry in many parts of the country. The present work is aimed at developing a concrete using the granite scrap an industrial waste, as a partial replacement for fine aggregate in self-compacting concrete. The percentage of granite fines addition by weight of fine aggre-gate is in the increment of 5%. The workability tests and hardened concrete tests has been conducted to determine the opti-mum percentage replacement of fine aggregate (M Sand) with granite fines in SCC. The optimum percentage replacement of fine aggregate by granite fines in SCC was found to be 15%. Behaviour of RC beams was also studied. From the various ob-servations, it can be concluded that granite fines (GF) can be used for the production of structural SCC

Index Terms—Granite fines, Self-Compacting Concrete, Slump flow test, L-box, V-box, U-box, RC beams. .

———————————————————— 1 INTRODUCTION

ARSH exploitation of natural resources by humans has been harshly criticized in re-

cent years. Every year millions of metric tons of granite waste pile is produced in Borba, and the Vila Vicosa region (the most important Portu-guese marble quarrying area), a by-product of the local quarrying industry. Fig. 1 shows enormous waste of granite fines produced 80–90% of the total volume of rock extracted [1]. It has therefore become necessary to create sus-tainable destinations for the waste material to mitigate. Using waste generated by the granite quarrying industry to produce fine aggregates for production of structural concrete has there-fore been studied as a useful alternative from the perspectives of environmental protection and sustainability of natural resources [1]. The granite stone industry generates different types of waste such as solid waste and stone slurry. This stone slurry is collected and processed to produce fine cakes. The compacted granite fine cakes are transported and disposed in landfills. Its water content are drastically re-duced approximately 2% and the granite fines

resulting from this will have environmental im-pacts. The factories were used to dispose these granite fines around their own factories. Disposal of these granite fines leads to health hazards like respiratory and allergy problems to the people around. It also decreases the fertility of soil and yield. It also causes Air and Water pollution. Cost of concrete can be reduced through the use of granite fines as an alternative measure to partial-ly replace fine aggregates in SCC with granite fines thus reducing the impacts caused by the fine particles [1]. Self – compacting concrete (SCC) is a fluid mix-ture, which is suitable for placing concrete at difficult conditions and also in congested rein-forcement, without vibration. The necessity of using concrete was proposed by Prof. Okamura in 1986 [2]. The size of dust particles is compati-ble with the purpose of filling up the transition zone (measuring between 10 to 50 microns) and the capillary pores (which range from 50nm to 10microns of diameter) this acts as micro filler in concrete [1].

H

———————————————— • AneesMphammed His currently pursuing masters degree pro-

gram in structural engineering, Mar- Baselios college of engineer-ing and technology, University of Kerala, India, PH-+919400677146. E-mail: [email protected]

• Tisny D Bis currently working as Assistant Professor, Mar- Baselios college of engineering and technology, University of Ke-rala, India, E-mail: [email protected]

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Fig. 1. Granite waste pile

2 EXPERIMENTAL INVESTIGATION 2.1 Materials Used Cement: Portland pozzolana cement (Ultra tech cement) conforming to IS 4031 is used for the study [6], [7], [8]. Fine aggregate: Manufactured sand (MSand) belonging to zone II of IS 383-1970 with a specific gravity of 2.64 is used as fine aggregate through-out the work [9]. Granite fines: Granite fines brought from Benoy Marbles and granites ambalamukku, is used as fine aggregate for partial replacement of Manu-factured sand. Tested physical properties are shown in Table 1.

TABLE 1

PROPERTIES OF GRANITE FINES

Coarse aggregate: Well graded crushed ballast stones of maximum size 12.5 mm size were used as coarse aggregate in concrete for the work. Super plasticizer:Cerahyperplast XR-W40 from ElkemPvt. Ltd. is used as the mineral additive in this study. Water: Potable water was used in the present investigation for both casting and curing.

TABLE 2

DETAILS OF SPECIMENS CAST

Type of specimen

Mould size

Total no. of speci-

mens

Cubes 150mmX150mmX150mm

63

Cylinders 150mm dia and 300mm ht

18

Prisms 100mmX100mmX500mm

6

Beams 150mmX100mmX1000mm

12

3MIX PROPORTION Based on the results of material properties, the mix design was carried out. The SCC design mix calculations were carried out as per the Japanese Method prescribed by Nan Su, et al. which strictly adheres to the EFNARC recommenda-tions [4], [5]. SCC trial mixes were prepared with varying percentages of silica fume, coarse aggre-gate, manufactured sand as fine aggregate and water to obtain SCC of M50 grade with target strength of 58.25N/mm2. For each prepared mix, the slump flow tests were carried out and after 28 days of curing, they were tested for target strength for M50 grade concrete. Accordingly, the mix proportion was adopted. Table 3 shows the various notations used for concrete mixes.

TABLE 3 NOTATIONS FOR CONCRETE MIXES

Control mix Notation SCC with fine aggregate NSCC

SCC with 5% FA re-placement

GFSCC-5


GFSCC-10


GFSCC-15


GFSCC-20


GFSCC-25

Table 4 shows the trial mix conducted for finding the control mix (NSCC) in SCC.

Properties Results

Specific gravity 2.556

Fineness modulus 2.55

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4 DETERMINATION OF OPTIMUM REPLACEMENT PERCENTAGE OF GRANITE FINES As per the mix proportion selected, various SCC mixes were prepared with 5%, 10%, 15%, 20% and 25% partial replacement of manufactured sand with granite fines. From these, the mix that gave slump flow results and adequate cube compressive strength after 28 days of curing was selected as the optimum replacement percentage. Table 5 shows the mix proportion details con-ducted for finding the optimum percentage re-placement of fine aggregate with granite fines. 4.1 Workability Tests

The influence of granite fines on the workability traits of SCC was determined with respect to slump cone test, U-box test, V-funnel test and L-box test. The tests were carried out as per the guidelines prescribed by EFNARC [5]. Based on the slump flow test and cube strength results, with reference to the EFNARC limits and target strength respectively, the mix that pro-duced acceptable slump flow result and target strength was adopted as the optimum granite fine replacement percentage to manufactured sand in SCC. Table 6 shows the workability properties of NSCC control mix and GFSCC-15 optimum mix found out. All the workability values were within the limit for the NSCC control specimens and GFSCC-15 specimens.

4.2 Evaluation of Mechanical Properties of NSCC

and GFSCC-15 Mixes

Various mechanical properties of NSCC and mix containing 15% partial replacement of fine ag-gregate by granite fines (GFSCC-15) were evalu-ated. Table 7 shows the mechanical properties of NSCC and GFSCC mixes.

TABLE 7 MECHANICAL PROPERTIES OF NSCC AND

GFSCC-15 MIXES

Mix

Desig-nation

Cube strength

(N/mm2)

Cyl-inder strength

(N/mm2)

Split ten-sile

strength

(N/mm2)

Flex-ural strength

(N/mm2)

Modulus of elas-ticity (N/mm2)

NSCC 57.01 47.96 3.96 5.2 3.87x104

GFSCC-15

55.96 47.66 3.78 5.1 3.70x104

GFSCC-15 specimens shows a slight decrease in all the mechanical properties of concrete as com-pared to the NSCC specimens. 4.3 Flexural and Shear Behaviour of RC Beams

The effect of granite fines on the flexural strength and shear characteristics of SCC beam specimens was evaluated by conducting two point loading test on beam specimens of size 100mm X 150mm X 1000mm on Universal Testing Machine of 1000kN capacity. Observations were recorded from the LVDTs for every 2.5kN load increments. The detailing of RC beams under flexural and shear behaviour test is asshown in Fig. 2 and Fig. 3. The detailing of beam specimens are done as per IS 456-2000 [10].

TABLE 6

WORKABILITY CHARACTERISTICS OF NSCC AND GFSCC-15 MIXES

Mix Desig-nation

Slump (mm)

T50 cm

slump Flow (sec)

L-box (H1/H2)

V-funnel (sec)

U-Box

(mm)

NSCC 708 4.5 0.82 12 30.50 GFSCC-15 715 4.5 0.84 12 30.40

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TABLE 4 MIX PROPORTION FOR NSCC

TABLE 5

MIX PROPORTION FOR GFSCC-15

Fig. 2. Beam detailing for flexural study

Mix Designa-tion

Cement

(kg/m3)

FA

(kg/m3)

CA

(kg/m3)

SF (%)

SP (%)

Water

(kg/m3)

Slump (mm)

Comp. stress

(N/mm2) NSCC 1 540 1008.20 751.93 5 1.3 162.54 695 37.67 NSCC 2 540 1008.20 751.93 5 1.4 167.40 700 33.47 NSCC 3 540 1008.20 751.93 5 1.5 156.60 690 38.99 NSCC 4 530 1008.20 751.93 5 1.5 164.30 700 44.21 NSCC 5 530 1008.20 751.93 7.5 1.5 159.53 685 46.67 NSCC 6 520 953.21 802.05 5 1.5 153.51 680 49.68 NSCC 7 520 953.21 802.05 5 1.5 166.40 705 47.23 NSCC 8 520 953.21 802.05 5 1.5 156.52 695 49.90 NSCC 9 510 953.21 802.05 5 1.5 158.10 710 54.99

NSCC 10 510 953.21 802.05 5 1.5 153.51 705 57.01 NSCC 11 500 953.21 802.05 5 1.6 150.50 690 51.11

Mix Desig-nation

Cement

(kg/m3)

GF re-placement percentage

(%)

FA

(kg/m3

)

GF (kg/m3

)

CA

(kg/m3)

SF (%)

SP (%)

Water

(kg/m3)

Slump (mm)

Comp. stress

(N/mm2)

NSCC 510 - 953.21 - 802.05 5 1.5 153.51 705 57.01 GFSCC-5 510 5 905.72 42.66 802.05 5 1.5 153.51 690 35.56 GFSCC-5 510 5 905.72 42.66 802.05 5 1.6 153.51 695 38.15

GFSCC-10 510 10 857.88 85.32 802.05 5 1.6 153.51 690 42.23 GFSCC-10 510 10 857.88 85.32 802.05 5 1.7 153.51 700 45.92 GFSCC-15 510 15 810.22 127.99 802.05 5 1.6 153.51 700 52.92 GFSCC-15 510 15 810.22 127.99 802.05 5 1.7 153.51 710 55.96 GFSCC-20 510 20 953.21 170.65 802.05 5 1.6 153.51 685 50.71 GFSCC-20 510 20 953.21 170.65 802.05 5 1.7 153.51 690 50.92 GFSCC-25 510 25 762.56 213.32 802.05 5 1.6 153.51 675 45.11 GFSCC-25 510 25 762.56 213.32 802.05 5 1.7 153.51 670 46.45

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Fig. 3. Beam detailing for shear study

Fig. 4. Testing of Beam

The ultimate load, deflection at increasing load in-tervals and crack width were recorded and the load-deflection curves and moment-curvature graphs were plotted for the specimens. Initial crack load, yield load, energy absorption, stiffness index, toughness and displacement ductility, curvature ductility indices of the specimens were calculated from the graph and the crack patterns were analysed to study the failure characteristics. 5 TEST RESULTS OF RC BEAMS 5.1 Failure Mode, Crack Pattern and Crack Propaga-tion The failure and crack patterns in each specimen is as shown in Fig. 5 and Fig. 6. It was observed that for GFSCC flexure specimens with 15% fine aggregate replacement by granite fines (GF), flexural cracks developed while in the case of GFSCC shear speci-mens with 15% FA replacement, shear cracks devel-oped before failure. The average crack width was however, smaller for both flexural and shear speci-mens with 15% fine aggregate replacement by gra-nite fines (GF) as compared to the control specimens. Fig. 7 shows the crack propagation of the GFSCC-15 flexure and shear beam specimens with respect to the control beam specimens. It was observed that for GFSCC-15 flexure and shear beam specimens the crack propagation was almost similar as compared

to the control beam specimens.

Fig. 5. Crack pattern and failure of NSCC and

GFSCC-15 flexure beam specimens

Fig. 6. Crack pattern and failure of NSCC and

GFSCC-15 shear beam specimens

Fig. 7. Crack propagation

5.2 Load-Deflection Characteristics Fig. 8 shows the load deflection graph of NSCC and GFSCC-15 beam specimens. It was observed that the curves for specimens with 15% granite fines and con-trol specimen showed similar load-deflection beha-viour with a linear portion till initial cracking and thereafter, non-linearly varying traits till the yield load.

0102030405060708090

0 0.5 1 1.5

Load

(kN

)

Crack width (mm)

NSCC-Flexure

GFSCC-15-Flexure

NSCC-Shear

GFSCC-15-Shear

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Fig. 8. Load-deflection graph

Beyond the yield point, the deflection of the beams increased considerably until the ultimate load was reached. Deformation of GFSCC-15 flexure and shear beam specimens was more as compared to the control beam specimens.

5.3 Evaluation of First Crack Load, Yield Load and Ultimate Load

TABLE 8 LOAD CARRYING CAPACITY

Specimen First crack load (kN)

Yield load (kN)

Ultimate load (kN)

NSCC-Flexure

22.5 68.4 85

NSCC-Shear

20 50 62.5

GFSCC-15-Flexure

25 67.2 84

GFSCC-15-Shear

22.5 48 60

Table 8 shows the similar load carrying capacity of GFSCC-15 mix with reference to the control mix un-der flexure and shear behaviour. However, the yield load slightly decreases with increase in fine aggre-gate replacement by granite fines (GF) due to the proportional decrease in compressive strength. The load taken by GFSCC-15 mix before the first crack under flexure behaviour was about 10% great-er than the control mix and the corresponding ulti-mate load taken was about 1% lower as compared to the control mix. Similarly the load taken by GFSCC-15 mix before the first crack under shear behaviour was about 15% greater than the control mix and the corresponding ultimate load taken was about 4% lower than that of control mix.

5.4 Energy Absorption, Stiffness and Toughness Although, GFSCC-15 flexure and shear beam speci-mens was capable of taking slight lower load than the control specimen, the energy absorption was higher than that of the control specimen for both the beams. This was due to the larger deflection carried by the GFSCC specimens in flexure and shear. However, the stiffness of GFSCC-15 flexure and shear beam specimens was lower as compared to the control beam specimens.

TABLE 9 ENERGY ABSORPTION, STIFFNESS AND

TOUGHNESS

Specimen

Energy absorption

(kNmm)

Stiffness index

(kN/mm)

Toughness

NSCC-Flexure

320.70 47.92 31.03

NSCC-Shear

239.32 43.56 33.47

GFSCC-15-

Flexure

435.74 40.33 41.99

GFSCC-15-Shear

291.70 41.97 49.97

5.5 Moment-Curvature Characteristics

0102030405060708090

0 2 4 6 8

Load

(kN

)

Deflection (mm)

NSCC-FlexureGFSCC-15-FlexureNSCC-ShearGFSCC-15-Shear

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Fig. 9. Moment curvature graph Fig. 9 shows the moment curvature graph of both specimens. Both the graphs clearly describes a high-er load carrying capacity of SCC mix with 15% fine aggregate replacement by granite fines (GF) with respect to the control specimen. The curvature was more for GFSCC-15 flexure and shear beam speci-mens as compared to the control beam specimens. 5.6 Displacement Ductility and Curvature Ductility From Table 10 the displacement and curvature duc-tility values was more for 15% fine aggregate re-placement with granite fines (GF) specimens under flexure and shear behaviour as compared to normal specimens, indicating similar load carrying capacity at smaller loads.

TABLE 10 DUCTILITY VALUES

Specimen Displacement

ductility Curvature ductility

NSCC-Flexure 1.44 4.59

NSCC- Shear 1.63 1.68

GFSCC-15- Flexure

1.90 4.76

GFSCC-15-Shear

1.99 2.00

5.7 Summary of Flexural and Shear Behaviour From the above results, it was concluded that the

flexural and shear capacity of GFSCC-15 specimens are comparable with that of control specimens. This is due to the reason that the voids present in the con-crete is filled up by the optimum amount of granite fines and also due to the effect of silica fume which fills in the micro-cracks thereby imparting greater strength characteristics. In the case of GFSCC-15 specimens, the larger surface area of the granite fines may enhance the bond strength characteristics with the reinforcing steel and also be the reason for small-er crack width, which induces effective interlocking property while bending thereby increasing the abili-ty to resist loads.

6 CONCLUSION 1. The workability and hardened properties of

GFSCC were comparable as that of NSCC spe-cimens

2. Optimum percentage replacement of fine aggre-gate by granite fines was found to be 15%

3. Reduction in compressive strength was ob-served with increase in replacement percentage of fin aggregate due to lower strength of GF. Decrease of 2% was obtained for GFSCC-15 spe-cimen for modulus of rupture

4. The load taken by GFSCC-15 specimens before the first crack under flexure and shear behaviour was about 10% and 15% greater than that of the control mix and the corresponding ultimate load taken was about 1% and 4% lower than that of the control mix

5. The crack pattern and crack width propagation developed for GFSCC-15 flexure and shear spe-cimens were similar as compared to the control mix

6. The load deflection and moment curvature curve of GFSCC-15 beam specimens showed similar pattern as compared to the control spe-cimens. The Energy Absorption Capacity and toughness was improved for GFSCC-15 flexure and shear beam specimens, while the stiffness decreased

7. Partial replacement of manufactured sand by 15% granite fines can be used for the production of structural SCC with the help of admixtures

REFERENCES [1] S. Diogo, G. Filipe, and B. Jorge, “Mechanical properties of structural concrete containing fine aggregates from waste gen-erated by the marble quarrying industry”, Construction and Building Materials, pp. 1-8, 2014 [2] H. Okamura, and M. Ouchi, “Self-Compacting Concrete”, Journal of advanced concrete technology, pp. 5-15, 2003

[3] M. Manikandan, and T. Felixkala, “Experimental Study on

0

2

4

6

8

10

12

14

0 0.5 1 1.5

Mom

ent (

kNm

)

Curvature (1/m)

NSCC-Flexure

GFSCC-15-Flexure

NSCC-Shear

GFSCC-15-Shear

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Properties of Granite Waste in Self Compacting Concrete”, Indian journal of applied research, pp. 128-130, 2015 [4] S. Nan , K. H. Hsu, H. W. Chai, “A simple mix design method for self-compacting concrete” Cement and concrete research, pp. 1799-1807,2001 [5] IS 383 - 1970 (Reaffirmed 1997), “Specifications for coarse and fine aggregate from natural sources for concrete”, Bureau of Indian Standards, New Delhi, India, 1970. [6] IS 456: 2000 (Reaffirmed 2005), “Plain and Reinforced Con-crete- Code of Practice", Bureau of Indian Standards, New Delhi, India, 2008 [7] EFNARC, (The European Federation of National Associa-

tions Representing for Concrete), “Specification and Guide-lines for Self-Compacting concrete", 2002. [8] IS 4031 (Part 4)-1988 reaffirmed 2005, “Methods of physical tests for hydraulic cement”, Bureau of Indian Standards, New Delhi, India, 1988. [9] IS 4031 (Part 5)-1988 reaffirmed 2005, “Methods of physical tests for hydraulic cement”, Bureau of Indian Standards, New Delhi, India, 1988. [10] IS 4031 (Part 6) -1988 reaffirmed 2005, “Methods of physi-cal tests for hydraulic cement”, Bureau of Indian Standards, New Delhi, India, 1988

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1 INTRODUCTION H IJSER€¦ · Anees Mohammed H, Tisny D B Abstract—Global consumption of natural river sandis very high due to the extensive use of concrete. The non availability